Thread: How to end a loop when valid entry is made

I am working on allowing a user to enter an ID # using JOptionPane. If the ID is valid, then it will display the ID#, student name, and GPA. If it is not valid, then the window should pop up again to allow the user to enter a valid ID. I have managed to get that far.

I am struggling with once a valid ID # is entered, how do I get the loop to stop? I have tried several different ways, but the code below is the most recent one, and it is still not working! Any help/suggestions to try would be greatly appreciated.

import javax.swing.*;
public class StudentIDArray
{
   public static void main(String[] args)
   {
      String enteredID;
      int idNumber;
      int x = 0; 
      String studentName = "";
      double studentGPA = 0.0; 
      boolean validID = false;
 
      int[] id = {1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010};
      String[] names = {"Bob", "Joe", "Fred", "Suzie", "Jane", "Megan", "Frank", "Jill", "Tom", "Judy"};
      double[] gpa = {3.5, 3.32, 3.7, 4.0, 3.72, 3.93, 2.6, 1.95, 2.18, 2.83};
 
      enteredID = JOptionPane.showInputDialog(null, "Enter a four-digit student ID number");
      idNumber = Integer.parseInt(enteredID);
 
      for(x = 0; x < id.length; ++x)
      {
         if(idNumber == id[x])
         {
            validID = true;
            studentName = names[x];
            studentGPA = gpa[x];
         }
      }
 
      if(validID == false)
         JOptionPane.showMessageDialog(null, "You entered an invalid ID number");
      else                   
         JOptionPane.showMessageDialog(null, "You entered " + idNumber + ".\nThe student's name is "
            + studentName + " and the GPA is " + studentGPA);                
   }
}

Do not use '==' to compare String objects. Use the equals() method instead.